Bra extenders, or bra hook extenders, are just like the back closures of your bras, with rows of eyes and a row of hooks at the back that can be inserted between hook tape and eye tape to lengthen the back band, making too-tight bra more comfortable, especially in experiencing temporary weight gain, like during pregnancy. These bra hook extenders may be removed and inserted to any of your bras as you will. 

This bra extender specification-- 
1) Fabric: nylon front, brushed back 
2) Size: 1/2" 3x5 
3) Metal parts: stainless steel hooks & square eyes 
4) Sealing: visible sealing 
5) Cutting: ultrasonic heat cutting 
6) Color:white. black, skin avialable